Heretofore, a device known as a flow packer has been employed for loading bulk powdered material such as cocoa, flour and the like into a container. The bulk material is then transported in the container to the processing facilities where the bulk material will be used. Sometimes a metallic substance and/or article may get into the container with the bulk material. Detection devices have been employed to determine the presence of such metallic substances and/or articles when the material is loaded into the container. Such detection devices provide a signal upon detecting metallic substances and/or articles to initiate an annunciation device for warning the operator of the flow packer that a metallic substance or article has been loaded into a container. A container having metallic contaminants may thus be removed and disposed of.
The annunciator type of indication has certain drawbacks which render it unsatisfactory. For instance, the annunciator is only active during the instant when the metallic substance or article is detected. Thus, it is likely that the operator could miss the annunciation and fail to remove the container with the metallic contaminant. Second, flow packers are often used in groups which operate concurrently. Thus, in the absence of special controls it is frequently not possible to determine in which machine a metallic contaminant has been detected. This is especially true when multiple annunciations are given simultaneously. Third, even when a contaminated container is identified and removed, it is possible that the contaminated container may be erroneously restacked with uncontaminated containers. Accordingly, mere annunciation of the detection of metallic contaminants leaves something to be desired.